Repton RT1 Ball Turning Tool

Hi all,

Has anyone had experience of using the Repton RT1 ball turning tool that is being advertised by one of the usual ME suppliers?

Any comments on it appreciated, as I am looking for a ball turning attachment, and this seems to fit the bill. The spec states the maximum diameter is 60mm - is there likely to be a practical minimum?

Thanks,

Anthony

Hi Anthony,
I have not used the Repton tool but I have used the Steve Bedair design which works very well. I would think the limitation on small sized is the size of the tool tip when it on the side of the ball is held in the remains of the rod from which it is turned.

Les.

Hi Anthony

Not that particular version but I have RDG's ball turning attachment which works well - not just for balls but also for cones. I suspect that it is a very similar device to the one mentioned above by Les.

Regards

Norman

Edited By NJH on 27/03/2014 20:22:15

To save anyone else curious the bother of googling, the device in question appears to be this one:

**LINK**

and the "usual ME supplier" is Chronos:

**LINK**

and to find a price you have to go to:

**LINK**

where it appears to sell for £89 inc VAT.

Edited By Bikepete on 28/03/2014 10:43:04

I bought one recently (being tight fisted, it seemed expensive - but looked a good piece of kit).

It is nicely finished, with minimal clearance toolholder to toolslide. (Made a packer to bring the toolbit to centre height and bent the operating arm (tough material - silver steel?) upwards to clear the clamp arm on my four way toolpost; probably much easier for folk with with Quick Change Toolposts.

The tool carrier slide rotates on a pretty substantial sealed ball race.

Made up a fixture clamping in place of the tool holder, to allow me to use my centre finder to position the cross slide on the centre line of the work piece). I then set the toolbit against the workpiece, and applied the cut by means of the topslide, along the axis of the lathe.

The instructions seem to indicate zeroing the cross slide dial with the toolbit on the centreline, retracting the cross slide, and then putting on the cuts with the cross slide until the dial reads Zero again, to produce a pure spherical end.

This may be a completely needless exercise on my part, due to not understanding the correct way to set it up, but it works for me!

Having used it three or four times, it worked well, (0.010" cuts without any chatter), on some steel (50mm dia studding) that did not seem to like delivering a good finish with any tool, to produce a hemispherical end on the workpiece.

Aluminium was a doddle.

The minimum diameter will be whatever is smallest diameter of material that you are turning. Obviously, to prevent problems such as spring, dig ins (and resulting scrap) the cut needs to be matched to the size and hardness of the material being machined.

Just for the fun of it, tried making a concave (which was impossible with the previous tool because of chatter and dig ins. Maybe I did not grind/set the toolbit correctly?).

No problems, so am am pleased with it, although it will probably not see very much use.

Like all tools, when you need it, almost impossible to work without it, but indispensible if you have one.

Howard

Good morning all,

I bought one of these directly from the manufacturer through ebay a while back. Despite sending two emails (Nov 2013) I have received zero response.

Here is the last email I sent:

Edited By Nick Moody on 28/03/2014 11:23:28

Edited By Nick Moody on 28/03/2014 11:24:04

Nick I have one of these and like you it is totally useless on steel ,bad finish ,poor clearance at the chuck end ,total waste of money.

my Hemingway one is so much better but as we all know it's made in the UK and has a bearing so it must be good

that my opinion but your mileage may vary, as a note I did a review as requested by a follow up email after purchase but guess what it's now are to be seen , maybe only good ones get thought the winge filter

Stuart

Like Norman, I too have the ball turner from RDG - another Christmas present (as I've already got lots of socks) !

Seems to work well enough (used on free-cutting steel) but my first job was to round one end of a centre nut for a Finger Plate I'd been making. I'd already turned and tapped it in anticipation of Father Christmas coming up with the goods but found that the front of the ball turner fouled the bottom of the chuck I was using on my Super 7. So it couldn't reach the work to round it.

I just found a longer length of bar and chucked it sticking out 2-3 inches. Turned & tapped it and I was then able to 'round' it OK, then part the new nut off. As I normally keep unsupported work as close to the chuck face as possible, it's something I will have to bear in mind when using this device. An "Up & Over" ball turner probably wouldn't suffer from this problem.

Thinking about it now (Note to Self !) I might also be able to get closer to short work (with the ball turner) using my ER32 chuck to hold the work as there is more clearance under it.

Regards,

IanT

I bought a Repton RT1 ball-making attachment from Chronos several months ago and I find it excellent. I have used it for making small stainless steel knobs for optical devices and the surfaces were so good that they needed little finishing with emery paper and metal polish.

The only fault I have found is a lack of information: for example the type of insert is not specified. I found that for steel the rhomboidal carbide inserts (Tungaloy type P GRADE , DCMT11T304-24) that fit my lathe tools happened to be right for the ball turner. There is also no information about dimensions, just the airy statement that it ‘fits all lathes’, which is not true.

I have attached a sketch of the device. The whole caboodle is supported by the shelf, which fits into the toolpost of the lathe. Your toolholder must be capable of accommodating the 9.5 mm thick shelf, which many quick-change types on small lathes cannot. The axis of rotation of the tool is fixed at 62 mm from the front of the shelf. If your toolholder cannot be retracted by this distance from the lathe centre you cannot fit the Repton: this rules out my EMCO Compact 5 lathe. Another requirement is that the lathe centre is at least 78mm above the bed, since the cutting tool is at this height above the end of the screw underneath the horizontal plate. A problem highlighted in an earlier posting is that the clearance between the handle and the lower surface of the shelf is maximally 120mm. This is quite generous, but apparently some toolposts need more: to check this, measure the height from the bottom of a tool shank to the highest point on your toolholder. If more than 120mm, your are OK. On my Colchester Master there is no problem fitting the Repton and I think this would be true of most larger lathes.

It would seem that this product is good but lacks vital sales information.

Correction: I made a mistake in my recent post: near the end it should have said 'If less than 120mm, you are OK because the handle will clear the top of your toolpost'.

I have just bought one direct from Repton (via e-Bay) and it seems first class. Also £10 cheaper than Chronos. It is well made and adjusts smoothly. When I try it out I will report further.

(Chester 920)

Seeing the comment about clearing/fouling the toolpost, the handle on mine did foul the top of my fourway toolpost. But since the end has been bent slightly, it no longer does! End of problem.

Howard

My thoughts were that it might be an interesting project to make modified especially in terms of using the type of toolbits I usually use.

My general feeling was that viewed like that it's over priced.

John

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John,

You might find this one interesting [if want something to fit the Pultra]

... it's worth a good look around his site.

MichaelG.

That is an interesting style for them Michael. Some people have used a boring head to achieve the same thing.

Interesting site.

John

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As John said
Here is my boring head  one  cutting 3/8"  Dia      Nobby

Edited By Nobby on 03/01/2016 23:20:37

I made something similar to a Repton out of odds and ends a while back and it works fine , in fact the first job for it was to make the ball ended handle , i used a ball race for the pivot bearing but found a bit of play was evident when used so I put a bronze thrust washer underneath and that solved the play problem.

Edited By Kettrinboy on 04/01/2016 09:14:11

Hang on, if I sell something cheaper than the next bloke, how am I being "greedy"? Can't have it both ways.

Ioan

Because they are selling retail direct at a lower price (but I should think at a larger profit margin) than they get supplying wholesale to Chronos. In other words they are acting both as wholesalers and retailers.